The “Internet of Things” (IoT) is envisioned to be a network of physical devices, vehicles, buildings and other items—embedded with sensors, electronics, software, actuators, etc. to enable network connectivity that will allow these objects to collect and exchange information. The IoT allows objects to be sensed and controlled remotely across existing network infrastructure, creating opportunities for more direct integration of the physical world into computer-based information systems, and resulting in improved efficiency, accuracy and economic benefit.
A “voltage controlled oscillator” (VCO) is an electronic oscillator whose oscillation frequency is controlled by an input voltage. The applied input voltage determines the instantaneous oscillation frequency. As a result, modulating signals applied to control the input may cause frequency modulation or phase modulation. Conventional VCO designs suffer from a plurality of issues, which include the following: 1. the gate DC voltage cannot be adjusted; 2. there is no negative Miller capacitor; and 3. there is no transformer feedback. For VCO designs that implement transformer feedback with a one-side resonator, in addition to lacking a negative Miller capacitor, the quality of the resonator is not optimized. For VCO designs with a start-up circuit, in addition to lacking a negative Miller capacitor, no transformer feedback is implemented.
An ultra-low power VCO is typically implemented in wireless sensor nodes, and also typically utilized in energy harvesting implementations such as thermo-electric generators. Ultra-low power and ultra-low voltage VCO's are typically achieved by the following implementations: sub-threshold design on gate terminal, near-triode design on drain terminal, transformer feedback, two-side resonators, and a negative Miller capacitor. Some examples of implementations include, but are not limited to cellular applications, Wi-Fi, Bluetooth low energy applications and Zigbee (IEEE 802.15.4).